/*
 * Copyright (c) 2008, Harald Kuhr
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice, this
 *   list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 *
 * * Neither the name of the copyright holder nor the names of its
 *   contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.twelvemonkeys.imageio.plugins.iff;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;

/**
 * IFFChunk
 *
 * @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
 * @version $Id: IFFChunk.java,v 1.0 28.feb.2006 00:00:45 haku Exp$
 */
abstract class IFFChunk {
    int chunkId;
    int chunkLength;

    protected IFFChunk(int chunkId, int chunkLength) {
        this.chunkId = chunkId;
        this.chunkLength = chunkLength;
    }

    abstract void readChunk(DataInput input) throws IOException;

    abstract void writeChunk(DataOutput output) throws IOException;

    protected static void skipData(final DataInput input, final int chunkLength, final int dataReadSoFar) throws IOException {
        int toSkip = chunkLength - dataReadSoFar;

        while (toSkip > 0) {
            toSkip -= input.skipBytes(toSkip);
        }

        // Read pad
        if (chunkLength % 2 != 0) {
            input.readByte();
        }
    }

    public String toString() {
        return IFFUtil.toChunkStr(chunkId) + " chunk (" + chunkLength + " bytes)";
    }
}
